chore: 添加缺失的静态资源文件

添加多个前端界面所需的图片、字体、音频等静态资源文件，包括：
- 管理员后台的图标、背景图、组件图片
- 移动端页面的商品图片、用户中心图片、活动图标
- 第三方库的示例图片和字体文件
- 浏览器兼容性配置文件
- 图标字体文件（eot、ttf、woff、woff2格式）

这些资源是前端界面正常显示所必需的，之前可能因版本控制忽略或遗漏而缺失。

vendor/symfony/mime/Header/DateHeader.php

@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Mime\Header;
+
+/**
+ * A Date MIME Header.
+ *
+ * @author Chris Corbyn
+ */
+final class DateHeader extends AbstractHeader
+{
+    private \DateTimeImmutable $dateTime;
+
+    public function __construct(string $name, \DateTimeInterface $date)
+    {
+        parent::__construct($name);
+
+        $this->setDateTime($date);
+    }
+
+    /**
+     * @param \DateTimeInterface $body
+     */
+    public function setBody(mixed $body)
+    {
+        $this->setDateTime($body);
+    }
+
+    public function getBody(): \DateTimeImmutable
+    {
+        return $this->getDateTime();
+    }
+
+    public function getDateTime(): \DateTimeImmutable
+    {
+        return $this->dateTime;
+    }
+
+    /**
+     * Set the date-time of the Date in this Header.
+     *
+     * If a DateTime instance is provided, it is converted to DateTimeImmutable.
+     */
+    public function setDateTime(\DateTimeInterface $dateTime)
+    {
+        if ($dateTime instanceof \DateTime) {
+            $immutable = new \DateTimeImmutable('@'.$dateTime->getTimestamp());
+            $dateTime = $immutable->setTimezone($dateTime->getTimezone());
+        }
+        $this->dateTime = $dateTime;
+    }
+
+    public function getBodyAsString(): string
+    {
+        return $this->dateTime->format(\DateTime::RFC2822);
+    }
+}